updated readme

Author: dwhitz

README.md

@@ -35,7 +35,7 @@ If you do not want to use them pass options --disable-libconfig, --disable-liblu
 
 On Ubuntu/Debian use: 
 
-     sudo apt-get install libreadline-dev libconfig-dev libssl-dev lua5.2 liblua5.2-dev libevent-dev libjansson-dev libpython-dev make 
+     sudo apt-get install libreadline-dev libconfig-dev libssl-dev lua5.2 liblua5.2-dev libevent-dev libjansson-dev libpython3-dev make 
 
 On gentoo: